Thanks again for the feedback!

OK, some I've come to the conclusion that my FTP is about 20-30 watts less than it was before I donated double red cells* on Jan 3. Here are two data points from Zwift (reported by Strava)

20-minute FTP test Jan 16, 2016 (the only time I did the Zwift FTP test):



Riding Zwift (without workout) on Dec 21, 2016:



Now, I'm thinking I should reduce my FTP on Zwift. However, I also know that as my red blood cells recover, I'm going to get stronger. So I could leave the FTP at it's current setting and be 'ok' failing to achieve all the intervals. Thoughts?

* if you're not aware, this is a blood donation where they take two units of blood. They separate the red blood cells, keeping the red cells and put the rest back in you (plasma & platelets). I've donated whole blood many times and never felt a significant effect, but the double RBC was a killer. Happily, based on my reading, [knocking on wood] I should be back to full strength (red blood count) by the time I get to my first race [/knocking on wood] - I have a 90-mile gravel grinder schedule for late March.